A.R. Hurson

Bio: A.R. Hurson is an academic researcher from Pennsylvania State University. The author has contributed to research in topics: Cache & Mobile computing. The author has an hindex of 2, co-authored 2 publications receiving 80 citations.

Transaction processing in mobile, heterogeneous database systems

Abstract: As technological advances are made in software and hardware, the feasibility of accessing information "any time, anywhere" is becoming a reality. Furthermore, the diversity and amount of information available to a given user is increasing at a rapid rate. In a mobile computing environment, a potentially large number of users may simultaneously access the global data; therefore, there is a need to provide a means to allow concurrent management of transactions. Current multidatabase concurrency control schemes do not address the limited bandwidth and frequent disconnection associated with wireless networks. This paper proposes a new hierarchical concurrency control algorithm. The proposed concurrency control algorithm, v-lock, uses global locking tables created with semantic information contained within the hierarchy. The locking tables are used to serialize global transactions, detect and remove global deadlocks. Additionally, data replication, at the mobile unit, is used to limit the effects of the restrictions imposed by a mobile environment. The replicated data provides additional availability in case of a weak connection or disconnection. Current research has concentrated on page and file-based caching or replication schemes to address the availability and consistency issues in a mobile environment. In a mobile, multidatabase environment, local autonomy restrictions prevent the use of a page or file-based data replication scheme. This paper proposes a new data replication scheme to address the limited bandwidth and local autonomy restrictions. Queries and the associated data are cached at the mobile unit as a complete object. Consistency is maintained by using a parity-based invalidation scheme. A simple prefetching scheme is used in conjunction with caching to further improve the effectiveness of the proposed scheme. Finally, a simulator was developed to evaluate the performance of the proposed algorithms. The simulation results are presented and discussed.

Semantic-Aware and QoS-Aware Image Caching in Ad Hoc Networks

Abstract: Semantic caching was originally used for structural data objects such as 2D location data and cannot be directly applied to mobile image data access. First, traditional semantic caching relies on exact match and therefore is not suitable for approximate and similarity-based queries. Second, the semantic description of cached data is defined on query context instead of data content, which leads to inefficient use of cache storage. Third, the semantic description of cached data does not reflect the popularity of the data, making it difficult to conduct popularity-driven content analysis and prediction. To facilitate content-based image retrieval in wireless ad hoc networks, we propose a semantic-aware image caching (SAIC) scheme in this paper. The proposed scheme can efficiently utilize the cache space and significantly reduce the cost of image retrieval. The proposed SAIC scheme is based on several innovative ideas: 1) multilevel representation of the semantic contents, 2) association-based and Bayesian probability-based content prediction, 3) constraint-based representation method showing the semantic similarity between images, 4) nonflooding query processing, and 5) adaptive cache consistency maintenance. The proposed model is introduced, and through extensive simulation, its behavior has been compared against two state-of-the-art ad hoc caching schemes as advanced in the literature.

Non-volatile memory cache performance improvement

Abstract: In order to provide a more efficient persistent storage device, one or more long-term storage media are included along with a non-volatile memory. In one embodiment, one portion of the non-volatile memory is used as a write buffer and a read cache for writes and reads to the long-term storage media. Interfaces are provided for controlling the use of the non-volatile memory as a write buffer and a read cache. Additionally, a portion of the non-volatile memory is used to provide a direct mapping for specified sectors of the long-term storage media. Descriptive data regarding the persistent storage device is stored in another portion of the non-volatile memory.

Storage platform for organizing, searching, and sharing data

Abstract: Various embodiments of the present invention are directed to a storage platform comprising a database engine, a data store, an application programming interface. The data store is implemented on the database engine for storing data therein, and the data store implements a data model that supports the organization, searching, sharing, synchronization, and security of data stored in the data store. Specific types of data are described in schemas. The application programming interface enables application programs to access services and capabilities of the storage platform and to access the data described in the schemas. The storage platform supports interoperability with existing file systems, enables users and systems to synchronize data stored in different instances of the data store, and provides the ability for application programs to be notified about and to track changes made to the data in the data store.

Systems and methods for the implementation of a digital images schema for organizing units of information manageable by a hardware/software interface system

Abstract: In an Item-based system, Images (e.g., JPEG, TIFF, bitmap, and so on) are treated as core platform objects (“Image Items” or, more simply, “Images”) and exist in an “Image Schema” that provides an extensible representation of an Image in the system—that is, the characteristics of an Image and how that Image relates to other Items (including but not limited to other Images) in the system. To this end, the Image Schema defines the properties, behaviors, and relationships for Images in the system, and the Schema also enforces rules about Images, for example, what data specific Images must contain, what data specific Images may optionally contain, how specific Images can be extended, and so on and so forth.

Systems and methods for interfacing application programs with an item-based storage platform

Abstract: Various embodiments of the present invention are directed to a storage platform (figure 20) comprising: a data store in which data stored therein is defined in terms of items, elements, and relationships (figure 20, 2014), wherein an item is a unit of data storable in the data store and comprises one or more elements, an element is an instance of a type (figure 20, 2016) comprising one or more fields, and a relationship is a link between at least two items; a set of schemas (figure 20, 2014) that define different types of items, elements, and relationships (figure 20, 2016); and an application programming interface (figure 20, 350a, 350b, or 350c) comprising a class (figure 20, 2008) for each of the different items, elements, and relationships defined in the set of schemas. Data may also be stored in the data store in the form of an extension to an existing item type, and wherein the application programming interface comprises a class for each different item extension (figure 20, 2006).

Systems and methods for synchronizing computer systems throuth an intermediary file system share or device

Abstract: The invention is directed to systems and methods for the synchronization of two clients both utilizing a common storage platform (2014, 2016) to synchronize through an intermediary (4102) that is not using the same common storage platforrn (2014, 2016). Data is synchronized using the existing capabilities of the intermediary (4102) but where the data structure of the clients is preserved. An adapter (4124) is used to enable a client to interact with an intermediary (4102) by compensating for the intermediaries (4102) inability to preserve the data structure elements inherent to the client's storage platform. Specific embodiments are directed to either or both upload-syncing data from a client to a intermediary (4102) and/or download-syncing data from an intermediary (4102) to a client. Certain additional embodiments are further directed to compaction of data on the intermediary (4102).